[IR] Remove check for bitcast of called function in CallBase::has/getFnAttrOnCalledFunction (#91392)

With opaque pointers, we shouldn't have bitcasts between function
pointer types.

Author: aeubanks

llvm/lib/IR/Instructions.cpp

@@ -454,24 +454,14 @@ bool CallBase::paramHasAttr(unsigned ArgNo, Attribute::AttrKind Kind) const {
 }
 
 bool CallBase::hasFnAttrOnCalledFunction(Attribute::AttrKind Kind) const {
-  Value *V = getCalledOperand();
-  if (auto *CE = dyn_cast<ConstantExpr>(V))
-    if (CE->getOpcode() == BitCast)
-      V = CE->getOperand(0);
-
-  if (auto *F = dyn_cast<Function>(V))
+  if (auto *F = dyn_cast<Function>(getCalledOperand()))
     return F->getAttributes().hasFnAttr(Kind);
 
   return false;
 }
 
 bool CallBase::hasFnAttrOnCalledFunction(StringRef Kind) const {
-  Value *V = getCalledOperand();
-  if (auto *CE = dyn_cast<ConstantExpr>(V))
-    if (CE->getOpcode() == BitCast)
-      V = CE->getOperand(0);
-
-  if (auto *F = dyn_cast<Function>(V))
+  if (auto *F = dyn_cast<Function>(getCalledOperand()))
     return F->getAttributes().hasFnAttr(Kind);
 
   return false;
@@ -485,12 +475,7 @@ Attribute CallBase::getFnAttrOnCalledFunction(AK Kind) const {
     assert(Kind != Attribute::Memory && "Use getMemoryEffects() instead");
   }
 
-  Value *V = getCalledOperand();
-  if (auto *CE = dyn_cast<ConstantExpr>(V))
-    if (CE->getOpcode() == BitCast)
-      V = CE->getOperand(0);
-
-  if (auto *F = dyn_cast<Function>(V))
+  if (auto *F = dyn_cast<Function>(getCalledOperand()))
     return F->getAttributes().getFnAttr(Kind);
 
   return Attribute();